WSMD working with stakeholders to develop guidance for the new water quality standard for de-icing salt residues.

Chloride levels in major New England rivers, relative to deicing salt sales.

In October of 2014, the Watershed Management Division (WSMD) completed a two-year effort to update the Vermont Water Quality Standards. A new feature of the updated standards are numeric criteria (aka allowable levels) for chlorides. Chloride is a chemical element in waters that comes from industrial and municipal wastewaters, agricultural wastes, and most commonly, deicing salts. At levels above the new criteria, chlorides can cause harm to aquatic life of streams, lakes, and wetlands. Urban streams in the greater Burlington area, typically small in size and surrounded by a high density of roads and housing, have documented high chloride concentrations. There are other small streams in Vermont that may have elevated levels, but are as-of-yet unassessed for this parameter. Chloride levels in Lake Champlain have been on the rise in recent years, but levels are well below levels-of-concern.

During the process of adopting the new chloride standards, the Division conducted several meetings with a variety of stakeholders. One consistent comment received was the need to develop guidance for how the new chloride criteria will be implemented, reflecting the fact that assessing the impacts from chlorides in surface waters is not quite so simple as filling a test-tube, and running a chemical analysis.

To this end, and to promote transparency among stakeholders, the Division is kicking off a process to develop an assessment and listing guidance for chloride. The guidance will address how individual waterbodies will be tested, how the data should be interpreted, and what actions may be taken to reduce chlorides where needed. To encourage discussion, the Division has developed a straw proposal and our scientists will be seeking stakeholder input to make sure the guidance reflects current knowledge and approaches for assessing and managing chlorides.

The first stakeholder meeting on January 28th presented relevant information about the new standards, and described the straw proposal developed by the Division. There will be additional meetings or other opportunity for stakeholder input as the assessment method is further developed.

If you, your municipality, or organization are interested in participating in this process, please contact Tim Clear at the WSMD: tim.clear@state.vt.us.

The Vermont Agency of Transportation is a leader in the development of chloride reduction approaches that balance public safety and water quality protection